Serviio

I'm running Serviio 2.3 on QNAP NAS as media server with BubbleUPnPserver for media playback with Chromecast. I have disabled transcoding for Serviio and only BubbleUPnP server has enabled transcoding. But processes on QNAP shows Serviio also running ffmpeg at very high CPU usage. This seem uneccesary when BubbleUPnPserver also running the transcoding and ffmpeg on high cpu usage?

Btw is HEVC coded video files unwatchable because of the lack of support for hardware transcoding with Intel Quick Sync Video in ffmpeg with QNAP and very high cpu usage in software transcoding.

Do you have burned in subtitles enabled on your Serviio setup? If so, that's the reason for FFMPEG running at full tilt. Burning in captions requires transcoding the video, and it will do so even with transcoding disabled.